The present invention relates to a method and the corresponding apparatus for the phonetic recognition of words spoken by a speaker, in which the speech is analysed periodically to obtain at least one vector to be compared with a plurality of vectors of reference phonemes and to select the phoneme most similar to the speech portion analysed.
Known types of apparatus for the recognition of words presuppose the cooperation of the speaker: in "speaker-dependent" types, recognition is based on comparison of the voice with words or with phonemes prerecorded by the same speaker, as samples or models. The sound is recognised when it is judged sufficiently close to one of the model words or phonemes. Consequently, the speaker is required to produce sounds similar, as far as possible, to the samples used for comparison.
In other systems, termed "speaker-independent", the speaker is required to conform to certain ways of pronunciation which are less precisely defined. This request may amount to a request to speak with "sufficient clarity".
In either case, in the event of lack of recognition, the speaker does not know the cause thereof and, consequently, he can only repeat the operation blindly, hoping for a better result. With experience, the user sometimes learns fortuitously to know the response of the machine and, gradually, the error rate decreases.